Although there are several types of bright macro lenses having a photographing view angle in a reference range and an F-number of about 3.5 or less for an interchangeable lens camera system, Gaussian-type lenses are widely known. In a macro lens, since it is desired that aberration correction is appropriately performed from the distance of closest approach to infinity, so-called a floating mechanism which causes at least two lens groups to be independently moved in order to perform focusing has been frequently used (refer to JP-A-2009-145587). In addition, other than the Gauss-type lens, a lens system has been proposed in which a first lens group having positive refractive power and a second lens group having negative refractive power are included, and the first lens group is moved in the optical axis direction when focusing is performed (for example, refer to JP-A-2009-210910).